Reversible watch

ABSTRACT

Reversible watch, comprising a case ( 1 ) provided with a first face ( 10 ) for displaying first time indications and a second face ( 11 ) opposite said first face. A turning-over mechanism ( 20, 21, 22, 23 ) allows the case ( 1 ) to be turned over around a turning-over axis ( 201 - 211; 221 - 231 ) parallel to the 6 o&#39;clock-12 o&#39;clock axis so as to display at the wearer&#39;s preference either the first face or the second face. The turning-over mechanism comprising a pivoting arm ( 20, 21; 22, 23 ) on each side of the case that allows the turning-over axis to be moved back. The case ( 1 ) is connected with the arms ( 20, 21; 22, 23 ) to be able to pivot around the turning-over axis ( 201 - 211; 221 - 231 ). The length of the arms is sufficient for turning over the case without the winding button or other buttons coming into contact with other parts ( 17 ) of the watch.

REFERENCE DATA

This application is a continuation of International Patent Application2004WO-EP050361 (WO04088436) filed on Mar. 24, 2004, claiming priorityof Swiss patent application 2003CH-0556 filed on Mar. 31, 2003, thecontents whereof are hereby incorporated.

FIELD OF THE INVENTION

The present invention concerns a reversible watch and a method forturning over a reversible watch case.

DESCRIPTION OF RELATED ART

By reversible watch, one will understand a watch whose case comprisestwo faces and a turning-over mechanism allowing the user to display,according to preference, one or the other face. At least one of thefaces comprises a dial with time indications; the opposite face bearseither another dial with other time indications, for example anothertime zone or complementary functions, or a protective cover that isfrequently decorated.

Reversible watches are for example known that comprise two mechanicalmovements for displaying for example two time zones on the two faces ofthe watch or for displaying the time on one face and auxiliaryfunctions, for example functions of chronograph, moon phase, date etc.,on the other face. Integrating two mechanical movements within a singlecase is however costly and requires a considerable thickness. Watchescomprising a single mechanical movement capable of displayingindications on both opposite faces are also known; such movements, whichare complex and often produced in limited quantities, are alsoexpensive. Watches comprising two quartz movements head-to-tail are alsoknown, but they have neither the advantages nor the prestige ofmechanical movements. These watches require in particular one or eventwo distinct batteries.

Different turning-over mechanisms have been conceived. For example,watches are known in which the bracelet is turned over with the case, sothat the inner side and the outer side of the bracelet and of the watchcan thus be inverted. This solution requires however reversiblebracelets and bracelet clasps, both sides of which must have a veryhighly-finished aesthetic.

Are also known watches in which the case pivots around a 9 o'clock-3o'clock axis, i.e. an axis perpendicular to the bracelet. Theturning-over mechanism in this case takes up the space around the caseusually allotted to the time-set button and other control elements,which implies strict aesthetic constraints for the watch designers andmanufacturers.

The most widespread reversible watches thus use a turning-over mechanismenabling the case to pivot around a 6 o'clock-12 o'clock axis in thebracelet's plane. Patent application FR2716353 for example describes awatch in which each end of the bracelet is connected to the case bymeans of a pivot making it possible to turn over the watch around the 6o'clock-12 o'clock axis. It is however necessary to remove the watchfrom the wrist to make the case pivot. Similar solutions enabling apivoting at the level of the bracelet's fastening are described notablyin the documents GB2213612, GB2241868, EP346660, CH659167, FR2583897,CH172421, CH138929, U.S. Pat. No. 4,470,708 and CH674291.

Different known solutions further propose to insert the case into anexternal frame connected with the bracelet and to make the case pivotrelative to the frame around a pivot, along the 6 o'clock-12 o'clockaxis. Examples of such watches are described in the documents CH159446,CH176988 and EP562522 notably.

In these solutions, the case is however connected to the external frameby a single pivot allowing a relative movement of the case along twodegrees of freedom. Such a pivot must thus be machined with a very highprecision, which makes the mechanism more expensive. Turning over thewatch requires moving the case relative to the frame along a complexthree-dimensional trajectory that is difficult to determine, andgenerally requires the user to hold the glass or glasses between hisfingers, leaving finger prints. Furthermore, the reliability of theturning-over mechanism is problematic since the pivot can jam/shrink oreven break under the effect of even small impacts or torsions. Finally,the case and in particular the protruding elements of the case, such ascontrol buttons, run the risk of coming into contact with the externalframe during pivoting, which may scratch and mark them.

Patent CH177310 describes a reversible watch comprising a case providedwith a pivot sliding in the slide of an external frame. Turning-over thecase is achieved by pivoting the case around the pivot until it reachesa vertical position, displacing the pivot in the slide, then completingthe pivoting of the case. In this case also the case is connected to theexternal frame through a single pivot, which causes reliability problemsand machining difficulties.

Other reversible watches comprise a turning-over mechanism allowing thecase to pivot around a 6 o'clock-12 o'clock axis use a case connectedwith an external frame by means of two pivots on the outer sides of thecase guided in slides of the frame. Solutions of this type have beendescribed notably in documents CH159982 and EP22255. In these watches,the reliability and solidity of the turning-over mechanism is improvedthanks to the connection of the case with the frame at two points;furthermore, the handling required for turning over is more intuitiveand does not require the glass to be touched. However, in thesesolutions, the case is turned over along an axis that is in a planeparallel to the watch and thus remains close to the bottom of theexternal frame. The lateral sides of the case must thus be adapted toallow the case to turn over without these sides touching the bottom ofthe external frame. In particular, it is impossible to place controlbuttons or winding buttons that are too protruding on the lateral sideof the case close to the turning-over axis, as these elements would thenrisk colliding with the frame's bottom during turning-over. Thissolution is thus not adapted to watches having control elements on twoopposed lateral sides, notably watches comprising simultaneouslyprotruding control elements on a first portion of the periphery of thecase between 12 o'clock and 6 o'clock and protruding control elements ona second portion of the periphery of the case between 6 o'clock and 12o'clock.

FR766809 describes notably a reversible watch comprising a turning-overmechanism allowing the case to pivot around a 6 o'clock-12 o'clock axis.The case is connected to two rods parallel to one another andarticulated relative to the watch case. The watch is turned over bylifting simultaneously the two rods and then turning over the caserelative to an axis connected with the two rods. It is necessary to turnover the case by orienting the watch's lateral side that is free of anywinding buttons towards the frame; the case could not be turned over ifit has control elements on both lateral sides, for example at both 3o'clock and 9 o'clock.

Furthermore, the case can pivot around the axis of the turning-over axiseven when the rods are only partially raised. The case and the windingbutton at this occasion risk coming into contact with the frame 21,which could scratch or even damage them.

Finally, in most of the described solutions, a large portion of theslides are apparent at least during certain turning-over steps, which isnot very aesthetic and especially risks them being exposed to dust orskin particles that can in certain cases block them and prevent thewatch from turning over. Finally, the slides are wearing parts thatcannot, or only with difficulty, be replaced when inaccuracies arise inguiding the case.

It is thus an aim of the present invention to propose a new reversiblewatch provided with a turning-over mechanism that avoids the flaws ofthe prior art turning-over mechanism.

In particular, it is an aim of the present invention to propose aturning-over mechanism that is sufficiently rigid and reliable and whichallows cases provided with protruding control elements on one or severalsides of the case to be turned over without these control elements orother parts of the case becoming damaged during turning-over.

It is another aim of the present invention to propose a turning-overmechanism in which the number of mobile parts is reduced in order tolower the manufacturing cost, to reduce the space requirements and toimprove reliability.

It is another aim of the present invention to propose a reversible watchcapable of offering a greater number of functionalities and displays onboth faces of the watch than the prior art reversible watches.

BRIEF SUMMARY OF THE INVENTION

According to the invention, these aims are achieved notably by means ofa reversible watch and a method comprising the characteristics of theindependent claims of corresponding type, preferred embodiments beingfurthermore indicated in the dependent claims.

In particular, these aims are achieved by means of a reversible watchcomprising a case provided with a first face for displaying first timeindications and with a second face opposite to said first face, at leastone element for controlling the watch's movement or movements protrudingon a first portion of the case's periphery between 12 o'clock and 6o'clock and at least one other element for controlling the watch'smovement or movements protruding on a second portion of the case'speriphery between 6 o'clock and 12 o'clock, a turning-over mechanism forturning over said case around a turning-over axis, said turning-overaxis being parallel to the 6 o'clock-12 o'clock axis duringturning-over, so as to display at the wearer's preference either saidfirst face or said second face. According to the invention, the case isconnected to pivoting arms so as to be able to pivot around aturning-over axis connected with the external frame; their length andarrangement are adapted to turn over the case without the controlelements coming into contact with other parts of the watch duringturning-over.

These aims are also achieved by means of a reversible watch comprising acase provided with a first face to display first time indications andwith a second face opposite to said first face, at least one element forcontrolling the watch's movement or movements. A turning-over mechanismallows the case to be turned over a turning-over axis, said turning-overaxis being parallel to the 6 o'clock-12 o'clock axis duringturning-over, so as to display at the wearer's preference either saidfirst face or said second face. According to the invention, theturning-over mechanism comprises an arm pivoting on each side of saidcase. The arms allow the turning-over axis to be displaced. The case isconnected to the arms to as to allow the case to turn over around theturning-over axis only when the arms are included by a predeterminedangle relative to the initial position. The length of the arms issufficient and their arrangements adapted to allow the case to be turnedover without the control elements or other parts of the case collidingwith other parts of the watch during turning-over.

This solution has the advantage of displacing the case's turning-overaxis during turning-over. It is thus possible to bring it in a morefavorable position, allowing voluminous watch cases or those providedwith protruding control elements on one or several faces to be turnedover without the case or control elements touching other parts of thewatch during turning-over.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood with the aid of thedescription of embodiments illustrated by the attached figures, inwhich:

FIG. 1 shows a view from above of a reversible watch according to afirst embodiment of the invention, in folded-down position with a handindicator on the visible face.

FIG. 2 shows a perspective view of the reversible watch according to thefirst embodiment of the invention, in folded-down position with a handindicator on the visible face.

FIG. 3 to 10 show different perspective views of the watch according tothe first embodiment of the invention, illustrated in differentsuccessive positions during turning-over.

FIG. 11 to 14 show different perspective side views of the reversiblewatch according to the first embodiment of the invention, illustrated indifferent successive positions during turning-over, in order to show inparticular the slide mechanism used in the first embodiment.

FIG. 15 to 18 show different perspective views of the reversible watchaccording to a second embodiment of the invention, illustrated indifferent successive positions during turning-over.

FIG. 19 shows a cross-sectional view of a watch case according to theinvention.

DETAILED DESCRIPTION OF POSSIBLE EMBODIMENTS OF THE INVENTION

FIG. 1 illustrates a view from above of a reversible watch according toa first embodiment of the invention. In this position, also illustratedin FIG. 2, the watch's face 10 comprising a hand indicator 100 isvisible on the upside of the watch, the other face 11 with analphanumerical display 110 visible notably in FIG. 10 being turned inthe direction of the wearer's wrist. To simplify the figures, thedisplay elements (hands or liquid crystal display) and the bracelet arerepresented only in the resting positions illustrated in FIGS. 1 and 10.

The watch comprises a case 1 containing the watch's movements andmounted in a frame 17 by means of a turning-over mechanism 2 describedfurther below. A bracelet 13 is fastened to the frame 17 through horns171. The movement controlling the hands' position can be wound up and/orreset by means of a winding button 16 on one of the lateral sides of thecase 1. Other control elements, here push-buttons 14, 15, allow otherfunctions of the watch to be controlled, notably functions displayed onthe watch's other face, as will be described further below. The controlelements 14, 15, 16 are distributed on two opposed lateral sides of thecase and thus occupy both the portion of the case's periphery between 12o'clock and 6 o'clock and the position comprised between 6 o'clock and12 o'clock. The control elements are protruding, which allows an easierhandling on both sides of the case 1.

The turning-over mechanism of this first embodiment comprises a pivotingarm 20 and 21 which, in folded-down position, covers the two opposedfront faces of the frame 17. In the illustrated embodiment, the case isrectangular or square and the length of the arms is more or less equalto the case's width. The arms can unfold in the manner illustrated inthe FIGS. 3 to 10 by pivoting in two vertical planes (i.e. perpendicularto the bottom 170 of the frame 17) around rotation axes 200 respectively210 connected to the frame 17. The angle of rotation achieved by the arm20 relative to its initial position is indicated in the figures by thereference α. The two rotation axes 200 and 210 of the two arms 20 and 21are parallel to one another and connected to diametrically opposedpositions of the frame 17.

The case 1 is connected to the two pivoting arms 20 and 21 through twopivots 201, 211 defining one turning-over axis. It can thus be turnedover around the turning-over axis 201-211 when the arms are unfolded. Inresting position, in order to display one of the faces 10 or 11, thearms 20, 21 are held by balls mounted on springs (not represented)engaged in holes 28 on the inner sides of the horns 171. A slightvertical force on the case 1 is sufficient to release the balls and freethe arms to unfold them in order to turn over the case.

As can be seen in FIGS. 3 to 10, the arms 20 and 21 enable the pivots201-211, and thus the turning-over axis, of the case 1 to be raised andaligned above the initial plane containing the upper face of the case inresting position. In this embodiment, the turning-over axis 201-211 thusmoves by pivoting the arms 20, 21 around the rotation axis 200-210during turning-over. The necessary handling for lifting the case 1 isthus intuitive and does not require complex movements. During all theturning-over phases, the arms 20-21 unitedly connect the case 1 with theframe 17.

The length of the two arms 20, 21 and the distance between the rotationaxes of the arms 200-210 and the case's turning-over axis 201-211 aresufficient to allow the case to turn over without the control elements14, 15, 16 or any other parts of the case 1 coming into contact with theframe 17 or with other parts of the watch. It is thus possible to switchthe displayed face 10 or 11 when the arms are unfolded without risk ofmarking, scratching or even damaging the control elements 14, 15, 16 orthe case 1. As illustrated notably in FIGS. 3 to 9, the two arms 20, 21remain parallel with opposed orientations during turning-over.

As can be seen in particular in FIGS. 11 c and 11 d representing a viewof the inner side of the arm 21, respectively a cross-section of thisarm along the axis Xld, the two arms 20, 21 each comprise a first slide202 (not represented) respectively 212 in the shape of an A, as well asa pivot 201 (not represented) respectively 211. The pivots 201respectively 211 move in second slides 250 respectively 260 in the shapeof an S machined in slide-holders 25 respectively 26 connected to thetwo front sides of the case 1. Inversely, the slide-holders 25respectively 26 each bear two guiding pivots 251 (not represented)respectively 261 moving in first slides 202, 212.

The case 1 being connected to the external frame 17 by the two arms 20,21 directed along opposed directions, it is displaced vertically,blocked in horizontal position and raises the two arms 20, 21. Bylifting the case 1, the pivot 211 moves in the S-shape slide 260connected with the case and simultaneously the two pivots 261 move inthe A-shaped slide 212. In the same manner, the pivots 251 move in theslide 202 of the arm 20 whilst the pivot 201 moves in the slide 250connected with the slide-holder 25.

The particular A-shape of the guiding slides 202, 212 as well as thelack of alignment of the two pivots 201 and 211 allow the case 1 to bekept horizontal, i.e. parallel to its initial resting position, in allpositions with the exception of the turning-over point illustrated inFIGS. 13 and 14. The two pivots 201 respectively 211 are incapable ofpivoting simultaneously, except when they are aligned in theturning-over axis, positioned at 6 o'clock and at 12 o'clock. In thisparticular position, the two pairs of guiding pivots 251 and 261 findthemselves in the circular portion of the slide 202 respectively 212.The slide-holder 26 can then pivot around the pivot 211, the two guidingpivots 261 being also free to turn in the circular portion of the firstslide 212. The slide-holder 25 performs a same turning-over movementaround the pivot 201.

The case 1 can thus, in this particular position only, turn freelyaround the horizontal turning-over axis 201, 211. In all the otherpositions of the arms 20, 21, the turning-over is blocked by the pivots201, 211 being non-aligned and by the pairs of pivots 251, 261 beingguided in their respective slides. There is thus no friction possiblebetween the front sides of the case 1 and the inner side of the arms 20,21.

In the illustrated embodiment, the turning-over point is reached whenthe angle α of inclination of the arms 20, 21 is equal to approximately50°, this value being chosen according to the arms' length and to thecase's total width to ensure a turning over without collision in theposition illustrated in FIGS. 4 to 8 and 13 to 14. It can thus beensured that no point of the case 1 or of the control elements 14, 15,16 comes into contact with the frame 17 when the arms 20, 21 areunfolded or folded down again.

The two pivots 201 and 211 define the turning-over axis around which thecase 1 can be turned over. As these pivots move in the second S-shapedslides 250, 260, the turning-over axis defined by the line connectingthe two pivots 201, 211 crosses the case 1 through the center alongdifferent directions when the arms 20, 21 are unfolded.

The non-rectilinear S-shape of the second slides 250, 260 allows thefriction forces exerted against the pivots 201, 211 to be controlled. Inparticular, this shape allows the reaction force exerted by frictionagainst the slides during unfolding and folding back of the arms 20, 21to be varied in order to achieve a more intuitive elastic unfolding andfolding-back effect. The turning-over mechanism could also function, ina less comfortable fashion, with rectilinear second slides 250, 260.

In a non-illustrated embodiment, the position of the slides and of thepivots on the case and the arms can be inverted. Furthermore, the “legs”of the A-shaped slides 202, 212 could be enlarged inwards so as toensure a contact at a single point of the pivots 251, 261 and thusreduce friction.

In order to turn over the case and display the watch's other face, thewatch wearer thus lifts the case 1 to disengage the spring balls fromthe holes 28, then pivots the arms 20-21 by 50° (in this example) untilthe turning-over position illustrated in FIGS. 4 to 8 and 13 to 14. Inthis position, the case 1 can pivot freely around the turning-over axis201-211, while being guided by the guiding pivots 251, 261, between thetwo opposed horizontal positions illustrated in FIGS. 4 and 7. The watchwearer then pushes the case 1 back to fold the arms 20 and 21 and reachthe second resting position illustrated in FIG. 10, with the second face11 visible. The case 1 is held in this position by balls on springs (notrepresented) engaged in other holes 28 on the inner sides of the horns171.

Slides 250, 260 united with the case 1 are wear parts. In a preferredembodiment, the slide-holders 25, 26 can thus be replaced without havingto replace the entire case. They are thus preferably mounted or screwedon the front sides of the case 1 by screws engaged in holes 24; theslide-holders 25, 26 can also hide screws (not represented) allowing thecase 1 to be opened for servicing or for replacing the battery.

It will be observed that the described device allows the case 1 to beturned over easily without having to remove the bracelet 13. It willalso be observed that the larger portion of the different slides ishidden by the arms 20, 21, the slide-holders 25, 26 and the case 1 inall positions, notably in the resting positions, so that the risk ofobstruction is considerably reduced.

The reversible watch of the invention advantageously comprises twodistinct movements 12, 19 (FIG. 19) lodged one against the other in thecase 1. The first movement 12 is a mechanical movement with manual orautomatic winding, allowing the time and possible supplementaryfunctions, for example a chronograph, to be displayed by means of hands100 on the watch's first face 10. The second movement 19 is anelectronic movement, for example a quartz movement, allowing otherindications, for example a second time, the date etc., to be displayedon the liquid crystal display 110 of the second face 11. The watch thuscombines the advantages of a hand indicator with those of analphanumerical display, as well as the advantages of a mechanicalmovement (prestige, operating without battery) with those of a quartzmovement.

A second embodiment of the invention is illustrated in FIGS. 15 to 18.This second embodiment has the advantage of not requiring slides in thecase 1, which allows use of a slimmer case. The slides are furthermorefragile elements, liable to become blocked in the case of mechanicalshocks or obstruction through dust or skin particles for example. Thisembodiment has however the inconvenience that it does not entirelyexclude the risk of contact between the case or the control elements andthe frame, as will be seen further below.

The watch according to the second embodiment of the invention isrepresented in FIG. 15 in folded down position with the face 10comprising an analog hand indicator 100 visible from above. It comprisesa case 1 connected in articulated fashion with an external frame 17 bymeans of two arms 22, 23. The arms are articulated relative to the frame17 around rotation axes 220, 230 (FIG. 12) one opposite the other,approximately at 6 o'clock and at 12 o'clock. The case 1 is capable ofpivoting relative to the two arms 22, 23 around a turning-over axisdefined by the two pivots 221, 231.

In this embodiment, as can be seen in FIGS. 16 and 17 in particular, thetwo arms 22 and 23 remain at all time parallel to one another. The case1 illustrated is square or rectangular; the length of the two arms 22,23 is lower than the length of this case, but sufficient for allowingthe case to turn over when the arms are entirely unfoldedperpendicularly to their initial position, without the control elements14, 15, 16 or other portions of the case coming into contact with theframe 17. The length of the two arms 22, 23, must thus be sufficient forthe distance between the rotation axes 220, 230 and the turning-overaxis 221, 231 to be sufficient to the sum of the half-length of the caseincreased by the thickness of said control elements.

The turning-over axis, defined as the line crossing the two pivots 221,231, crosses the case along a fixed direction parallel to the 6o'clock-12 o'clock diameter but different from this diameter. Since thecase 1 is fastened to the arms 22, 23 by axes without slides, the anglebetween this turning-over axis and the case 1 remains constant duringthe entire turning-over. The connection between the arms 22, 23 and thecase is thus more rigid than in the first embodiment.

In the resting position illustrated in FIG. 15 with the analog face 10visible and in FIG. 18 with the numerical face 11 visible, the arms 22,23 come to lodge in folded down position in a hollow of the case 1. Theturning-over mechanism is thus almost hidden in folded down position.

In order to turn over the case 1 and chose the face 10 or 11 to display,the watch wearer lifts the case 1 from the resting position illustratedin FIG. 15 to release the balls on springs from the holes 28, thenpivots the two arms 22, 23 in a vertical plane until the case 1 issufficiently far away from the frame 17 to allow the case to rotatewithout colliding. The case can then pivot easily around theturning-over axis 221, 231 to choose the visible face 10 or 11 todisplay. The arms then continue their rotation by 180° to fold back inthe other resting position illustrated in FIG. 18.

As compared with the first embodiment, the control elements 14, 15 and16 can possibly in this second embodiment come into contact with thebottom of the frame 17 if the case is turned over too fast or too late,i.e. when the angle α traveled by the arms 22, 23 is considerablydifferent from 90°. Indeed, since the two pivots 221, 231 are alwaysaligned, a turning-over is possible at any point. Furthermore, the case1 does not remain horizontal during all phases of the displacement.

1. Reversible watch, including: a case provided with a first face fordisplaying first time indications and a second face opposite said firstface, at least one control element of the movement or movements of thewatch, a turning-over mechanism for turning over said case around aturning-over axis, said turning-over axis being parallel to the 6o'clock-12 o'clock axis during turning-over so as to display at thewearer's preference either said first face or said second face, whereinsaid turning-over mechanism includes a pivoting arm on each side of thecase, said arms allowing said turning-over axis to be displaced, saidcase being connected with said arms so as to allow said case to pivotaround said turning-over axis only when said arms are inclined by apredetermined angle relative to its initial position, the length of saidarms being sufficient and their arrangement adapted to allow said caseto be turned over without said control elements colliding with otherparts of the watch during turning over.
 2. The watch of claim 1,including at least one control element of the movement or movements ofthe watch protruding on a first portion of the case's periphery between12 o'clock and 6 o'clock and at least one other control element of themovement or movements of the watch protruding on a second portion of thecase's periphery between 6 o'clock and 12 o'clock.
 3. The watch of claim1, wherein said arms allowing said turning-over axis to be lifted abovethe initial plane containing the upper face of the case in restingposition.
 4. The watch of claim 1, including a frame connected with thewatch's bracelet, said case being inside said frame in each of the tworesting positions, said turning-over mechanism connecting unitedly saidcase with said frame during all phases of said turning-over.
 5. Thewatch of claim 4, said arms closing two opposite front sides of saidframe in folded-down position.
 6. The watch of claim 1, said casepivoting relative to said arms around two pivots, said turning-over axisbeing defined by the line crossing said pivots.
 7. The watch of claim 6,said arms being arranged so as to displace said pivots along a singledegree of freedom.
 8. The watch of claim 7, said arms being capable ofpivoting around a fixed rotation axis.
 9. The watch of claim 1, saidcase being rectangular or square, the length of said arms being more orless equal to the width of said case.
 10. The watch of claim 1, saidarms being oriented along different directions during turning-over, saiddirections being oriented along two planes parallel to one another. 11.The watch of claim 6, said turning-over axis crossing said case throughthe center.
 12. The watch of claim 6, each arm being connected on theone hand to said frame to be able to pivot around said rotation axis,said rotation axis being fixed relative to said frame, each arm beingfurthermore connected in pivoting fashion with said case around saidpivots, said pivots being mobile relative to said case.
 13. The watch ofclaim 1, said arms being each connected with said case through at leastone pivot moving in at least one slide during turning-over.
 14. Thewatch of claim 6, said turning-over axis defined by said pivots crossingsaid case through the center along different directions when said armsare unfolded.
 15. The watch of claim 1, said case and said arms furtherincluding two guiding slides and at least two guiding pivots, at leasttwo guiding pivots traveling in each of said guiding slides, so as tomaintain said case parallel to its initial resting position until theturning-over point.
 16. The watch of claim 1, said arms each includingat least one pivot traveling in one slide connected with the case, saidcase including at least one pivot traveling in one slide connected toeach of said arms, the arrangement of said slides and of said pivotsallowing said case to be kept parallel to its initial resting positionuntil the turning-over point.
 17. The watch of claim 16, including atleast two pivots sliding in at least one same of said slides, the shapeof said slide being adapted to prevent said two pivots from pivotingexcept in one point corresponding to said turning-over point.
 18. Thewatch of claim 16, including at least one other slide connected to saidcase shaped like an S.
 19. The watch of claim 1, said predeterminedangle allowing said case to turn over without said case touching saidframe.
 20. The watch of claim 6, said turning-over axis crossing saidcase parallel to the 6 o'clock-12 o'clock diameter of said case.
 21. Thewatch of claim 20, said turning-over axis being fixed relative to saidcase during the entire turning-over.
 22. The watch of claim 1, said armstraveling in planes parallel to one another during turning-over.
 23. Thewatch of claim 20, said case being rectangular or square, the length ofsaid arms being lower than the width of said case but greater than thesum of the half-length of the case increased by the thickness of saidcontrol elements, so as to allow said case to be turned over withoutsaid control elements coming into contact with other parts of the watchduring turning-over.
 24. The watch of claim 20, said arms coming tolodge in folded down position in a hollow of said case.
 25. The watch ofclaim 20, each arm being connected on the one hand to said frame to beable to pivot around said rotation axis, said rotation axis being fixedrelative to said frame, each arm being furthermore connected in pivotingfashion with said case around said pivots, said pivots being fixedrelative to said case.
 26. The watch of claim 20, said arms allowingsaid pivots to pivot around a rotation axis connected with said frame.27. The watch of claim 1, including: a first movement for displayingfirst time indications on a first face, a second movement for displayingsecond time indications on a second face opposite said first face,control elements on both diametrically opposed faces of said case forcontrolling both said movements.
 28. The watch of claim 1, including: afirst movement for displaying first time indications on a first face, asecond movement for displaying second time indications on a second faceopposite said first face, wherein said first movement is of mechanicaltype and in that said second movement is of electronic type. 29.Reversible watch, including: a case provided with a first face fordisplaying first time indications and a second face opposite said firstface, at least one control element of the movement or movements of thewatch on a first lateral side of said case and at least one othercontrol element of the movement or movements of the watch on a secondlateral side of said case opposed to said first lateral side, aturning-over mechanism for turning over said case around a turning-overaxis, said turning-over axis being parallel to the 6 o'clock-12 o'clockaxis during turning-over so as to display at the wearer's preferenceeither said first face or said second face, wherein said turning-overmechanism comprises a pivoting arm on each side of the case, said armsallowing said turning-over axis to be displaced, said case beingconnected with said arms so as to pivot around said turning-over axis,the length of said arms being sufficient and their arrangement adaptedto allow said case to be turned over without said control elementscolliding with other parts of the watch during turning over. 30.Reversible watch, including: a case, a first movement for displayingfirst time indications on a first face, a second movement for displayingsecond time indications on a second face opposite said first face, aturning-over mechanism for turning over said case so as to display atthe wearer's preference either said first face or said second facewherein said first movement is of mechanical type and in that saidsecond movement is of electronic type.